ROLE OF LOW-ENERGY SECONDARY ELECTRONS IN SYNCHROTRON RADIATION-EXCITED CHEMICAL-VAPOR-DEPOSITION OF SILICON-NITRIDE FILMS

The dependence of the deposition rate on the radius of the synchrotron radiation (SR) beam, on the incident angle to the substrate and on su bstrate configuration to SR-excited chemical vapor deposition of silic on nitride films. Through the experimental results and related analyse s, the contribution of gas-phase excitation near the substrate surface to deposition is clarified. In addition, by evaluating the numbers of photoelectrons and secondary electrons emitted from the SR-irradiated substrate, the contribution of low-energy secondary electrons to the excitation of gas-phase and adsorbed molecules is discussed. Finally, a reaction model including the excitation of the core electrons of sub strate constituent atoms and the contribution of the interaction betwe en generated low-energy secondary electrons and gas-phase molecules an d adsorbates near/at the surface is proposed to explain the material d ependence of the film composition observed in the SiH4 + NH3, gas syst em. (C) 1997 American Vacuum Society.